STAFF working in Merseyside tax offices are facing abuse, overcrowding and stress following the new tax credit shambles.

Union bosses say most customers are understanding - but some staff have faced anger, frustration and even death threats from irate clients.

Workers are now being offered special training in how to deal with angry callers.

The new tax system - which targets working families - has been plagued with problems since its launch at the beginning of April.

Now staff at tax centres in Liverpool and Bootle are facing a rise of around 500% in customers dropping in for help - as well as severe overcrowding in offices and swamped phone lines.

Jim Harrow, regional spokesman for the Public and Commercial Services Union, which represents 5,500 tax staff in the north west, said: "It has been an extremely difficult period for staff, who are facing a massively increased workload.

"Some centres are having to close their doors early just to make sure they can help the people already inside. The queues are enormous.

"Most people are understanding - but tempers can boil over. It only takes one confrontational situation to go wrong for it all to become very serious, which is why they need special training in how to handle such situations."

The union, together with the Inland Revenue, are introducing a range of measures to help ease the situation.

The measures include:* New agreements on overtime* The setting up of specialist contact centres to deal with the excess work* Signing for the nearest toilet and nappy changing facilities to ease the situation for families who face a long wait.

The New Tax Credit was introduced this year to provide extra income for working families. Despite an extensive TV advertising campaign, the system for processing applications soon became overloaded, with computer problems adding to the chaos.

Thousands of families were left without payments, or with outstanding queries on their applications.